Voice calls in communication networks may be established using signaling messages such as origination messages. Origination messages may contain an automatic number identification (ANI) field that is intended to identify a calling number originating the voice call and an identity of the subscriber associated with the calling number. For example, John Smith may have a mobile phone associated with phone number 555-555-1234. When John Smith dials a toll-free number, an origination message may be sent by the communication network to an interactive voice response (IVR) system associated with the toll-free number, and the ANI of that origination message may identify the calling number as 555-555-1234 and may identify the subscriber associated with the calling number as John Smith. In some cases, however, the ANI can be spoofed. Said in other words, using technology such as an ANI-spoofing application, a call origination message may be initiated by a different calling device than John Smith's mobile phone that nevertheless carries an ANI that identifies the calling number as 555-555-1234 and the subscriber associated with the calling number as John Smith.